Improvement in joints for boat-knees



J'. w. sANBonN. JOINT F-oa Bgm.' ENEES." No.184,z65. 4 unarmed 11017.14,187e.

TH l: GRAPHIC CD.N.Y.

UNITED STATES PATENT OFFICE.

JOSEPH W. SANBORN, OF KINGSTON, NEW HAMPSHIRE.

IMPROVEMENT IN JOINTS FOR BOAT-KNEES.

Specification forming part of Letters Patent No. l 84,265., datedNovember 14, 1876; application filed July 22, 1876. j i

.To all whom it may concern Be it known that I, J osEPH W. SANBORN ofKingston, Rockingham county, New Ham pshire, have invented certainImprovements in Boat-Timbers, of which the following is a specication Myimprovements relate to a method of constructixlg timber for boats, bywhich I obtain great strength, with lightness and durability, andconsist as hereafter explained.

lhe drawings accompanying this specification represent, in Figure l, aside view, and in Fig. 2 a section, of a timber embodying my invention.Fig. 3 is a view of the strip of wood prior to being bent. Fig. 4 is alike View after being bent, and showing the pockets for receiving theteat ot' the stay-plates, (to be explained.) Figs. 5 and 6 are views ofone ofthe said stay or clamp plates.

In carrying my invention into practice, I provide a strip, A, of wood,of a thickness to produce oneor more timbers, and of a width equal tothe widest part of such timber; and I cut from one side ot' such stripof Wood, at the point wherethe bend is to be under, an obtuse-anglednotch, B,of such form that when the strip is bent to the destined shapethe side of the notch shall meet and form a perfect miter, as shown inFig. 4 of the drawings. The slope ot' the sides ofthe notch will, ot'course, vary with the angle ot' the sides of the bent timber, and willbe determined by trial. At the corner or point of connection ot' eachside ofthe notch with the bottom thereof I cut in the strip A, andlongitudinal therewith, a short saw-kerl', a, in order to permit of therequisite slip of the parts as the sides of the not-ch approach eachother.

I next, by preference, steam the strip A, and then bend it about themold or form from whichv it is to receive its ultimate shape, as

shown in Fig. 4, the curved portions b b of the edges of the strip beingproduced before or after bending, as may be deemed best.

It will be observed thatI leave a small por tion, e, of Wood intactbelowthe saw-kerf a a. This is to obtain strength, and I leave so much of thewood at this point as can be bent with safety and not produce too largea corner.

To strengthen and stiien 'the joint above described I employ twometallic plates or ears, c c, and I place them upon opposite sides ofthe strip and covering joint, and rivet them together, as shown in Fig.2 ot' the drawings.

To greatly strengthen the parts I prefer to cast upon the inside of eachplate c a series of Jfeats, d d, &c., which extend a short distance intothe wood, but not entirely through, lest too much of the latter shouldbe taken away. When the teats d are employed the rivets should passthrough them, as shown in Fig. 3.

Boat-timbers formed as above described are superior to natural-bendtimbers, for the reason the grain ot' the wood follows its lengththroughout, and the corner or bend is equally strong.

I claim as my invention, and desire to secure by Letters Patent, thefollowing:

1. The joint herein described, producedy by the notch B and saw-kerfs a,a, substantially as and for purpose stated.

2. In combination with the timber formed with notch B and saw-kerfs a a,and bent as described, the strengthening-plates c, litted to the jointon opposite sides of the timber, provided with teats d, let into thewood, and united by rivets which pass axially through the teats, asshown and set forth.

JOSEPH W. SANBORN.

Witnesses F. CURTIS, W. E. BOARDMAN.

